As a non-magnetic ceramic material used for manufacturing a ceramic multilayer component having an inductor portion that uses a non-magnetic ceramic including a borosilicate glass, a non-magnetic ceramic that includes a borosilicate glass containing 70 to 90 percent by weight of SiO2, 10 to 30 percent by weight of B2O3, and 5 percent by weight or less of K2O is known (see Patent Document 1).
Since the dielectric constant of a non-magnetic ceramic layer of the inductor portion is extremely low when this non-magnetic ceramic is used, as compared to that of a ferrite magnetic layer, it has been believed that a self-resonant frequency can be significantly increased, the inductor portion is easily applied to a high frequency region, and the degree of freedom of structural designing of ceramic multilayer components can be improved.
As a method for manufacturing a multilayer ceramic circuit board using a photosensitive material, a method for manufacturing a multilayer ceramic circuit board in which a photosensitive ceramic paste and a photosensitive conductive paste are sequentially processed by exposure, development, and lamination is known (see Patent Document 2).
According to this manufacturing method, it has been believed that a multilayer ceramic circuit board having a high wire density can be efficiently manufactured.
A glass containing SiO2, B2O3, and K2O (hereinafter also referred to as “Si—B—K-based glass”), which is usable according to Patent Document 1, has low viscous fluidity during firing. Accordingly, for example, when firing a laminate of glass layers containing this Si—B—K-based glass and conductor layers containing Ag as a conductive component laminated thereto, degradation in insulating properties between the layers caused by diffusion of the conductive Ag into the glass layers (insulating layers) can be suppressed or prevented; hence, the glass described above is a preferable material for that reason.
However, since a Si—B—K-based glass has inferior wettability to a ceramic aggregate, such as alumina, which is included in a glass paste as a filler (for example, a contact angle: 90° or more), a long firing treatment must be performed in order to obtain a dense glass layer (insulating member).
As the firing time is increased, voids are generated in a sintered body (sintered laminate of a multilayer wiring chip component or the like) and/or Ag is diffused, so that the insulating properties between the layers are disadvantageously degraded.
Also in the case in which a conventional photosensitive glass paste is used that includes, a glass other than a Si—B—K-based glass as disclosed in the above Patent Documents 1 and 2, a problem similar to that described above actually occurs to greater or lesser degrees.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 10-87342
Patent Document 2: Japanese Unexamined Patent Application Publication No. 8-18236